Snow moisture integrator

ABSTRACT

A snow moisture integrator for automatically measuring and recording changes in moisture content related to the surface of a snow pack includes two spaced vertical conduits interconnected by a horizontal conduit. The conduits are positioned in the vicinity of the snow pack and are substantially filled with a non-freezing liquid. A sample holding assembly, including an open top receptacle for holding snow and a float rod connected to the receptacle, floats in the column of liquid in one of the vertical conduits. A float is operatively connected to a continuous stage recorder and floats in the column of liquid in the other vertical conduit. A sample of snow in the receptacle is exposed to the same ambient conditions as the snow pack. As the weight of the snow sample varies, either a loss of weight due to evaporation or a gain of weight due to condensation, the float rod rises or sinks in the liquid in the vertical conduit. The change in amount of liquid thus displaced by the sample holding assembly is reflected in a change in the liquid level in the other vertical conduit. The float responds to the liquid level changes in the conduit and this movement is recorded thereby providing a record of weight changes in the snow sample and, hence, the amount of evaporation and condensation.

United States Patent Santeford, Jr. et al.

[ Sept. 12, 1972 [54] SNOW MOISTURE INTEGRATOR [72] Inventors: HenryS.Santetord, Jr., Fort Collins, Colo.; John G. Meier, Negaunee; George R.Alger, Dollar Bay,

290,097 11/1931 Italy ..177/207 Primary Examiner.lames J. GillAttorney-John W. Michael, Gerrit D. Foster, Bayard H. Michael, Paul R.Puemer, Joseph A. Gemignani, Robert E. Clemency, Andrew 0. Riteris,Glenn A. Buse and Spencer B. Michael [57] ABSTRACT A snow moistureintegrator for automatically measur ing and recording changes inmoisture content related to the surface of a snow pack includes twospaced vertical conduits interconnected by a horizontal conduit. Theconduits are positioned in the vicinity of the snow pack and aresubstantially filled with a non-freezing liquid. A sample holdingassembly, including an open top receptacle for holding snow and a floatrod connected to the receptacle, floats in the column of liquid in oneof the vertical conduits. A float is operatively connected to acontinuous stage recorder and floats in the .column of liquid in theother vertical conduit. A sample of snow in the receptacle is exposed tothe same ambient conditions as the snow pack. As the weight of the snowsample varies, either a loss of weight due to evaporation or a gain ofweight due to condensation, the float rod rises or sinks in the liquidin the vertical conduit. The change in amount of liquid thus displacedby the sample holding assembly is reflected in a change in the liquidlevel in the other vertical conduit. The float responds to the liquidlevel changes in the conduit and this movement is recorded therebyproviding a record of weight changes in the snow sample and, hence, theamount of evaporation and condensation.

12 Claims, 1 Drawing Figure surface of a snow pack.

'1 SNOW MOISTURE INTEGRATOR BACKGROUND OF THE INVENTION scientificpurposes or as a monitor for potential snow slides, one'of the importantparameters is the changes in moisture content in the snow pack resultingfrom evaporation or condensation.

This parameter can be measured by manually taking samples of the snowpack at regular intervals and analytically determining moisture contentof the samples by conventional techniques or by other similar manualtechniques. However, such a procedure is extremely time consuming andthe accuracy of the data obtained thereby is highly dependent upon theparticular sampling and/or moisture-determination techniques employed.Also, any changes in the moisture content between the times of samplingare not measured. Continuous measurement and recording is most desirablebecause it provides acapability of evaluating-hour to hour, day to day,and even month to month changes with respect to other existingatmospheric conditions, such as wind velocity, barometric pressure,relative humidity, etc. It is further desirable that the measurementsand recording thereof be done automatically to minimize manpowerrequirements. In order to obtain meaningful data, the. measuring meansemployed should be subjected to the actualenviro'nment surroundingthesnow pack. Therefore, the measuring means must be capable of operatingin adverseweather conditions, and preferably, should be simply con-.

structed in order to rninimize initial fabrication and maintenancecosts.

SUMMARY OF INVENTION A primary object of this invention is to provide asimple, inexpensive method and means for continuously and automaticallymeasuring and recording the moisture content, and changes therein,related to the The snow moisture integrator of this invention includes arecording means and an open receptacle adapted to hold a sample of thesnow pack. Separate and spaced vertical conduits and an interconnectingconduit are filled to a predetermined level with a liquid, preferablyone having a freezing point substantially below the minimum temperatureexpected in the vicinity of the snow pack. The conduits are connected sothat a displacement of liquid in the first of these vertical conduitsproduces a corresponding change in the level of the liquid in the secondvertical conduit. The sample holding receptacle floats in the column ofliquid in the first vertical conduit and a float, operatively connectedto the recording means, floats in the column of liquid in the secondvertical conduit.

The first vertical conduit and sample-holding receptacle are positionedin the immediate vicinity of the snow pack being evaluated. Preferably,a sample of snow is taken from the surface of the snow pack and placedin the receptacle, and the top surface thereof is exposed to the sameambient conditions as the snow pack. As the weight of the snow samplevaries, either a loss of weight due to evaporation or a gain of weightdue to condensation, the buoyancy of the sample holding assemblychanges, causing a change in the amount of liquid it displaces in thevertical conduit. This change in liquid displacement in the firstvertical conduit produces a corresponding change in the liquid level inthe second vertical conduit which is measured and recorded by therecording means as the float connected thereto responds to the liquidlevel changes. Hence, the recording means, which is calibrated toindicate moisture content, continuously measures and records themoisture content, and changes in moisture content, of the sample.

' Since the sample is exposed to they same ambient conditions as thesnow pack, the measured changes in moisture content are representativeof the evaporation and condensation at the surface of the snow pack. Thesample holding receptacle is preferablycovered with a means whichdiffuses strong winds to prevent the sample from being blown out of thereceptacle, but yet permits free circulation of the ambient air over thesurface of the sample.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is a side elevational,partially cross-sectional view of a snow moisture integrator embodyingthis invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The snow moisture integrator ofthis invention is installed in the vicinity ofthesnow pack for which themoisture content is to be measured. It includes a sample holdingassembly 10 comprised of a receptacle 12, constructed from a lightweight material and arranged to hold a sample of snow 14 from the snowpack 15, a screen 16, and a float rod 18 attached to the bottom 20 ofreceptacle 12. Receptacle 12 is open at the top so that the top surfaceof sample 14 is exposed to the ambient conditions at the snow pack.Screen 16, which is removable fits either inside or over the side walls22, 24 of receptacle 12 and diffuses strong winds to prevent sample 14from being blown out of the receptacle, but yet, permits freecirculation of the ambient air over the surface of the sample.

Cylindrical, vertical conduits 26, 28 and horizontal conduit 30interconnecting and establishing liquid communication between thevertical conduits, contain a liquid 32, which is preferablynon-freezing, i.e. has a freezing point substantially below the minimumambient temperature expected in the vicinity of the snow pack.Generally, any low viscosity liquid which will not freeze, orsubstantially solidify, at this minimum ambient temperature can be used,such as ethylene glycol, mixtures of water and antifreeze additives,motor oils, transmission oils and the like. If desired, the conduits canbe provided with heating means and a thermostatic control, in which caseliquids having higher freezing points can be used. Although anyconvenient support means can be used, the bottom portions of verticalconduits 26,28 and horizontal conduit 30 are preferably buriedunderground in the vicinity of the snow pack to provide support asshown. If desired, the conduits can be mounted on a mobile support sothe device can be easily moved to different locations.

Float rod 18, constructed from a light weight material and preferablytubular with a closed bottom 34, slidably fits inside vertical conduit26 so that the sample holding assembly is generally free to float in thecolumn of liquid in vertical conduit 26. Float rod 18 is centered withinconduit 24 to maintain receptacle 12 in a horizontal position andminimize frictional contact between the inside walls of conduit 24 andthe outside surfaces of float rod 18. This can be accomplished byproviding conduit 24 with low friction means 36, such as O-rings, whichare in slidable engagement with outside surfaces of float rod 18. Shield38 extending over the upper end of conduit 24, prevents snow fromentering the space between conduit 24 and float rod 18.

Continuous stage recorder 40 of conventional design, positioned onplatform 42, includes a stylus or pen (not shown) which cooperates witha continuously moving graduated chart (not shown) to make a permanentrecording. The stylus or pen is operatively connected to actuator means44, such as a pulley. Float 46 floating in the column of liquid invertical conduit 26 is operatively connected to actuator means 44 bycable 48. Cable 48 includes a counter weight 45 so that, when float 46moves up and down as the liquid level in conduit 26 rises and falls,actuator means 44 is rotated and'this in turn actuates the recorder torecord the amount of liquid level change.

For operation of the device a sample of snow is placed in receptacle l2and screen 16 is installed. The sample holding assembly 10 sinks intothe column of liquid in conduit 24 displacing an amount of liquidequivalent to the total weight of the sample and sample holdingassembly. This is transmitted to conduit 26 through conduit 30 toestablish an equilibrium condition. As the weight of sample 14 varies,either a gain of weight due to condensation or a loss of weight due toevaporation, the buoyancy of sample holding assembly 10, and hence theamount of liquid displaced thereby, changes correspondingly. This changein liquid displacement is reflected in a change in the liquid level inconduit 26. Float 46 responds to the liquid level changes in conduit 26and this change is permanently recorded by the recorder. The recordercan be calibrated so that a predetermined deflection of the stylus orpen resulting from movement of float 46 corresponds to a known amount ofchange in the moisture content of the sample. Hence, both losses andgains of moisture in the sample are continuously and automaticallymeasured and recorded. Since the sample holding assembly is installed inthe vicinity of the snow pack and is open to the atmosphere, the sampleis subjected to the same environmental conditions as the snow packitself. Therefore, the measurements are representative of the actualconditions of the surface of the snow pack and errors introduced bymanual sampling analytical techniques are substantially eliminated.

With exception of the recorder, which can be covered with a protectiveenclosure, all the components of the device are preferably constructedfrom materials which are capable of extended periods of exposure to theoutside conditions without deterioration. As a guide for constructing asnow moisture integrator embodying this invention, receptacle 12 can betwo feet square and constructed from a light weight blown plasticmaterial, such as Styrofoam. Float rod 18 can be constructed from anacrylic resin plastic, such as Plexiglas, and has an outside diameter of6 inches. Conduit 26 can also be constructed by an acrylic resinplastic, such as Plexiglas, and has an inside diameter of 6.5 inches.Conduits 28 and 30 can be constructed from plastic tubing having aninside diameter of one-half inch. Screen 16 is constructed from a lightweight, conventional hardware cloth having openings approximatelyone-half inch square. Liquid 32 is ethylene glycol and conduits 26,28are positioned approximately l0 feet apart. The size of receptacle l2and diameters of float rod 18 and conduit 26 can be varied considerablywithout varying the inside diameter of conduits 28, 30. Of course,larger receptacles will provide better statistical results because ofthe larger surface area of the sample held thereby; however, the overallconstruction costs are increased substantially because of the addedstructural support required and the larger sizes required for conduit 26and float rod 18.

From the above detailed description, it can be seen that this inventionprovides an extremely simple, yet highly reliable, method and means forcontinuously and automatically measuring and recording both the additionand loss of moisture to a representative sample of snow from the snowpack being evaluated. Since liquid displacement is utilized as thetechnique for determining changes in moisture content, the measurementsare unaffected by the physical state of the sample, i.e. the moisturecan be in the form of solid snow or liquid.

We claim:

1. A snow moisture integrator comprising,

first and second vertical conduits spaced apart and interconnected by agenerally horizontal conduit so that said vertical conduits are inliquid communication, said conduits containing a liquid with a column ofliquid being defined by each of said vertical conduits;

recording means;

a float operatively connected to said recording means and floating inthe column of liquid in said first vertical conduit;

a sample holding assembly adapted to hold a sample of snow from a snowpack for which the moisture content is to be measured and furtheradapted to float in the column of liquid in said second vertical columnso that a change in the buoyancy of said sample holding assembly,corresponding to a change in the weight of said sample, produces achange in the liquid level in said first conduit, said liquid levelchange in said first vertical conduit being recorded by said recordingmeans as said float responds thereto; and

means for locating said second conduit and said sample holding assemblyin the vicinity of said snow pack so that the snow held in said sampleholding assembly is exposed to the same environment as the surface ofsaid snow pack.

2. The snow moisture integrator according to claim 1 wherein said sampleholding assembly includes a generally flat receptacle for holding saidsample which is open at the top to expose said sample to theenvironmental conditions at said snow pack.

3. The snow moisture integrator according to claim 2 wherein said liquidhas a freezing point substantially below the minimum ambient temperatureexpected in the vicinity of said snow pack.

' sample so as to prevent it from being blown from said receptacle butpermits substantially free circulation of the ambient air over thesurface of said sample.

6.-The snow moisture integrator according to claim including a shieldpositioned over the upper end of said 1 second conduit to prevent theentry of snow into said second conduit.

7. The snow moisture integrator according to claim 1 wherein the bottomportion of said vertical conduits and said horizontal conduit aremounted underground.

8. The snow moisture integrator according to claim 3 wherein saidreceptacle is constructed from a light weight, blown plastic material.

9. The snow moisture integrator according to claim 5 wherein saidvertical conduits and said float rod are .cylindrically shaped and saidfloat rod is tubular with a closed bottom.

10. A method for determining the changes in the moisture content in thesurface of the snow pack comprising,

arranging conduit means containing a liquid to define first and secondvertical liquid columns, said liquid columns being in liquidcommunication with each other; providing means for holding a sample ofsnow'from the snow pack, said snow sample being exposed to theenvironmental conditions at said snow pack;

floating said sample holding means in said first liquid column so thatthe amount of liquid displaced therein, corresponding to the combinedweight of said sample and sample holding means, is reflected by changesin the liquid level of said second liquid column; and

measuring said changes in the liquid level of said second liquid column.

11. The method according to claim 10 wherein said measuring anddetermining is accomplished by a float means floating in said secondliquid column operatively connected to a means calibrated to indicatethe amount of and changes in moisture in said sample.

12. A method according to claim 11 wherein said calibrated means is acontinuous stage recorder.

1. A snow moisture integrator comprising, first and second verticalconduits spaced apart and interconnected by a generally horizontalconduit so that said vertical conduits are in liquid communication, saidconduits containing a liquid with a column of liquid being defined byeach of said vertical conduits; recording means; a float operativelyconnected to said recording means and floating in the column of liquidin said first vertical conduit; a sample holding assembly adapted tohold a sample of snow from a snow pack for which the moisture content isto be measured and further adapted to float in the column of liquid insaid second vertical column so that a change in the buoyancy of saidsample holding assembly, corresponding to a change in the weight of saidsample, produces a change in the liquid level in said first conduit,said liquid level change in said first vertical conduit being recordedby said recording means as said float responds thereto; and means forlocating said second conduit and said sample holding assembly in thevicinity of said snow pack so that the snow held in said sample holdingassembly is exposed to the same environment as the surface of said snowpack.
 2. The snow moisture integrator according to claim 1 wherein saidsample holding assembly includes a generally flat receptacle for holdingsaid sample which is open at the top to expose said sample to theenvironmental conditions at said snow pack.
 2. The snow moistureintegrator according to claim 1 wherein said sample holding assemblyincludes a generally flat receptacle for holding said sample which isopen at the top to expose said sample to the environmental conditions atsaid snow pack.
 3. The snow moisture integrator according to claim 2wherein said liquid has a freezing point substantially below the minimumambient temperature expected in the vicinity of said snow pack.
 4. Thesnow moisture integrator according to claim 3 wherein said sampleholding assembly includes a vertical float rod connected to the bottomof said receptacle, said float rod being slidably mounted inside saidsecond vertical conduit and partially submerged in the column of liquidtherein.
 5. The snow moisture integrator according to claim 4 whereinsaid sample holding assembly includes diffusing means connected to saidreceptacle and covering said sample, which diffuses winds passing oversaid sample so as to prevent it from being blown from said receptaclebut permits substantially free circulation of the ambient air over thesurface of said sample.
 6. The snow moisture integrator according toclaim 5 including a shield positioned over the upper end of said secondconduit to prevent the entry of snow into said second conduit.
 7. Thesnow moisture integrator aCcording to claim 1 wherein the bottom portionof said vertical conduits and said horizontal conduit are mountedunderground.
 8. The snow moisture integrator according to claim 3wherein said receptacle is constructed from a light weight, blownplastic material.
 9. The snow moisture integrator according to claim 5wherein said vertical conduits and said float rod are cylindricallyshaped and said float rod is tubular with a closed bottom.
 10. A methodfor determining the changes in the moisture content in the surface ofthe snow pack comprising, arranging conduit means containing a liquid todefine first and second vertical liquid columns, said liquid columnsbeing in liquid communication with each other; providing means forholding a sample of snow from the snow pack, said snow sample beingexposed to the environmental conditions at said snow pack; floating saidsample holding means in said first liquid column so that the amount ofliquid displaced therein, corresponding to the combined weight of saidsample and sample holding means, is reflected by changes in the liquidlevel of said second liquid column; and measuring said changes in theliquid level of said second liquid column.
 11. The method according toclaim 10 wherein said measuring and determining is accomplished by afloat means floating in said second liquid column operatively connectedto a means calibrated to indicate the amount of and changes in moisturein said sample.
 12. A method according to claim 11 wherein saidcalibrated means is a continuous stage recorder.